Sheet abrasive material



Patented June 29, 1926.

, v I 1,591 ,o01 UNITED [STATES PATENT OFFICE.

HENRY JOSEPH, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO UNITED STATESSAND PAPER COMPANY, OF WILLIAMSPORT, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

, No Drawing.

This invention relates to improvements in sandpaper, emerycloth, etc.,and more particularly sandpaper or emery cloth made with a waterproofcement binder for the abrasive. The sandpaper or emery cloth of thepresent invention is not only Waterproof but is also fireproof.

Sandpaper and emery cloth, when made with a waterproof cement, areinflammable and combustible.

not only during its manufacture, but also during its transportation andstorage, and also during its use, where sparks resulting from its usemay suflice to set fire to the inflammable material.

The present invention provides an improved sheet abrasive such assandpaper or emery cloth, which is Waterproof and also fireproof orincombustible in the sense that it is not readily inflammable andresists comthe waterproof cement.

bustion.

According the the present invention, both the paper or cloth backing,and thew'ateb proof cement used, are fireproofed, so that the resultingabrasive sheet is made up of both a fireproof backing and a fireproofand waterproof cement for the abrasive material.

The backing employed may be paper or cloth backing such as is nowcommonly employed in making sandpaper and emery cloth. It is speciallytreated, however, by a fireproofing treatment to make it fireproom orincombustible. The waterproof cement employed may be varied. It may bemade, for example, of the usual varnish ingredients, such as oils,resins, etc., but there is added to the cement and compounded therewith,suitable fireproofing ingredients, so that the resulting waterproofcement is also fireproof and contains in its composition appropraitefireproofing ingredients.

Different'fireproofing agents may be employed both for fireproofing thepaper or cloth backing and for compounding with The paper or clothbacking may be treated or impregnated with a solution of thefireproofing agent or agents, or the fireproofing agent or agents may beused or incorporated into the paper or cloth, for example, during itsmanufacture, in order to render it fireproof. A saturated aqueoussolution of ammonium sulfate is satisfactory ifor this purpose. The

SHEET ABRASIVE MATERIAL.

Application filed May 12, 1925. Serial no. 29,838.

The inflammable char acter of the material adds to the fire hazard,

nlzlssu'so solution may be applied hot or cold to the paper or fabric,depending on how readily the paper or cloth absorbs the solution offireproofing material. The paper or cloth may then be allowed to dry inthe air or in a drying ovenbefore the Waterproof hinder or cement isapplied.

The waterproof adhesive or cement may be made from drying oils and gumandresins in the way varnishes are made, with the addition of driers orsiccatives to hasten the drying or curing operation, and fireproot ingmaterials are added and compounded therewith in such proportion as torender the adhesive or cement substantially fireproof When used inmaking the abrasive paper, cloth, or other desirable product.

The varnish oils, resins, driers, etc., connnonly used in makingwaterproof varnish composition, are well known in the art, as well asthe thinnersor solvents,'like turpentine, for thinning the compositionto faganic or inorganic compounds which are of a suitable character torevent burnin of the product and to ren er it substantially fireproofparticularly when employed in the composition in substantial amounts. I

The invention will be further illustrated by the following specificexample describing a flexible. waterproof cement or adhesivev which isalso fireproof. In the formula given, the parts are byuweight.

Blown linseed oil 1400 Varnish gum (copal) 100Q Manganese resinate 30Triphenylphosphate 400 Ammonium sulphate; .400

The actual mixing and compounding of the gum, oil, and drier may be doneas in the manufacture 'of varnishes'Q The gum may be fused and heateduntil the required amount of distillation has occurred in order that thegum may compound readilywith the oil. The heated oil may then be addedin small portions at a time with stirring. The drier may be added to theheated oil, or the fused gum when ready to take the oil, or to thecompounded resin and oil. The triphenyl phosphate'may be added to thecompounded resin, oil, and drier while still hot. After cooling to about100 (1., the

finely powdered ammonium sulphate may be stirred into the compoundedmixture. The

for securing the abrasive to the cloth or paper. That is, the paper orfabric may be rendered waterproof, as well as fireproof, by theapplication to both sides thereof of the fireproof and waterproofcomposition, such as the composition above mentioned. So also, if thepaper or fabric has previously been fireproofed by an independenttreatment, it may be waterproofed on both sides with the fireproof andwaterproof compositions, and the abrasive may be applied to one side orto both sides of the paper or fabric so treated. Where the abrasive isapplied only to one side of the paper or fabric, the other side may betreated with a light water proofing treatment suflicient to render itwaterproof, and this waterproofing will be accomplished withoutsacrificing the desired fireproof character of the waterproof prodnot.

For special purposes, the second coating may be dispensed with, but suchsecond coatings are customary in the art.

Where the adhesive and abrasive are applied to only one side of thesheet, the other side may be waterproofed by treating with any suitablewaterproofing material, but this waterproofing material, as aboveindicated, is advantageously one which contains fireproofing agents. Asomewhat diluted mixture made, for example, by diluting the abovecomposition with a solvent, or made by compounding a drying oil withsuitable fireproofing material, may be used for this purpose. Such awaterproofing and fireproofing composition may be applied before orafter the abrasive si e is prepared. In some cases, the waterproof andfireproof compositions ap lied to the two sides of the paper: orclot maybe suficient to render grit b suitable means thereon. Where the sheet 1scoated on both sides with the abra-- sive, top coats of the cement maybe applied to one or both sides, or, in some cases, such top coats maybe omitted.

After the application of the waterproof cement and of the abrasive thesheet material is dried or cured, for example, by hanging it in the airor in a warm room or in an oven. The curing may tlms be effective byhanging the sheet material in a room or oven heated to between and 100C., and by supplying warm air to hasten the drying and curin e. g., bypolymerization, oxidation, etc., o the adhesive and waterproofingmaterials.

In general, he method of applying the waterproof cement, by spreading1tevenly over t e paper or fabric, and by applying the powdered abrasivethereto (such as emery powder, glass powder, etc.) is similar to thatcommonly employed when using glue and othermaterial as adhesive orcement, and the drying or curing of the cement may be carried out in thesame way that varnish films or layers are commonly dried or cured toconvert, the varnish films into a waterproof film or coating.

The improved product of the present invention so obtained is asubstantially waterproof and in addition a substantially fireproofabrasive sheet, with both the sheet acking and the waterproof cement, aswell.

as the powdered abrasive material itself, fireproof or incombustible inthe sense that they resist combustion and prevent burning of the productor render the material sub stantial y fireproof.-

Variations can be made in the amounts and proportions of the ingredientsused, as well as in the ingredients themselves, and in the particularprocedure employed in makin the new composite fireproof and waterproosheet abrasive without departing from the spirit and scope of theinvention.

It will thus be seen that the invention provides a new and improvedsheet abrasive which has the important advantage of being fire resistantor fireproof, and that the sheet abrasive is fireproofed both in thesheet backing and in the adhesive cement applied thereto. While theadvantages of the invention the backing or the cement, the portion whichis not fireproofed remains combustible,

while by specially fireproofing both the backing and the adhesive, acomposite product is obtained which is substantially fireproof orfire.resistant throughout, even though it is made up of a cloth or paperbacking and of a varnish composition which, without the fireproofingtreatment or ingredient,

would be of a readily combustible or inflammable nature. The presentinvention accordingly makes ossible the utilization of ingredients whichcommonly give a readily combustible'or inflammable product, but with theproduction instead of a substantially incom ustible, or fireproof, orfire resistant product. e

sive, and a stable and permanently flexible adhesive for securing saidabrasive to said backing, which adhesive is waterproof and fireproof andremains fireproof and retains its adhesive and flexible properties afterbeing thoroughly wetted. 3. A flexlble sheet abrasive materialcomprising a flexible fireproof and waterproof backing, a fireproofabrasive, and a stable and permanently flexible adhesive for securingsaid abrasive to said backing, which adhesive is waterproof andfireproof and remains fireproof after being thoroughly wetted.

4. Sheet abrasive material comprising sheet backing and a waterproofcement for the adhesive secured thereto, said cement containin triphenylphosphate.

5. S eet abrasive material comprising sheet backing and a waterproofcement for the adhesive secured thereto, said cement con-v tainingammonium sulphate.

6. Sheet abrasive material comprising sheet backing and a waterproofcement for the adhesive secured thereto, said cement containingtriphenyl phosphate and ammonium sulphate, In testimony whereof I affixmy signature.

HENRY JOSE-PH.

